A student once asked the Buddha:Master Gotama, what is the cause and condition why somehuman beings are healthy while others are often sick ?

The Blessed Buddha then explained:Here, friend, some man or woman is in the habit of injuring living beings
with the hand, a stone, with a stick, another instrument or with a knife!
Because of intending and performing such action, at the breakup of
the body, right after death, such one is reborn in a state of affliction, in a
painful destination, in the purgatory, or even in the hells...But if such one at the
breakup of the body, after death, is not rebornin an awful state, a painful destination, the purgatory, or in the hells,
but instead comes back to the human state, then wherever such one is reborn such one is weak, fragile, unhealthy & sick #!
These are the actions, friend, leading to future disease: Injuring living
beings with the hand, with a stone, stick, other instrument or with a knife!However, friend, any man or woman, who avoids injuring any living beings
with the hand, with a stone, with a stick, other instrument or with a knife,because of intending & undertaking such action, at breakup of the body,
right after
death, such one reappears in a pleasurable & happy destination, even in the divine dimensions! But if at the breakup of the body, right after
death, such one is not reborn in a happy destination, in the heavenly worlds,
but instead comes back to a human state, then wherever such one reappears,such one is well & healthy %! This is the way, friend, leading to health, to be
exact: Avoiding all injuring, harming & afflicting of any living sentient being
whether with the hand, with any stone, with any stick, or with any knife!...

#: Such one escapes hell, because the evil kamma is modified by
past good!%: Such one miss heaven, because the good kamma is modified by past evil!